The invention relates to a disposable Injector with a cylinder/piston unit that can be filled at least temporarily with active substance, with a housing in which a pretensioned and releasable mechanical spring energy reservoir is arranged, and with at least one piston-actuating ram positioned between the spring energy reservoir and the piston of the cylinder/piston unit.
Such an injector is disclosed in U.S. Pat. No. 8,105,271 B2 issued Jan. 31, 2012 to the present assignee.
DE 10 2007 031 630 A1 discloses, among other things, an injector of this type. With the exception of the mechanical spring of the spring energy reservoir, almost all the components of the injector are produced expensively from plastics by injection moulding. Components that are subject to high mechanical loads are additionally reinforced with glass fibres.
Therefore, the problem addressed by the present invention is that of developing a disposable injector of modular design which, with a small overall size, comprises only a small number of components and, while being easy to handle and inexpensive to produce, ensures safe storage and operation.